There are numerous devices which are used as clamps on pipes, bars, shafts and the like. By way of example, devices for retaining weights on a bar used for weightlifting applications are well known. In weightlifting, disk shaped weights are typically mounted, alone or in combination, on a bar by inserting the bar through a hole in the center of each disk. The combination of the bar and weights is typically referred to as a barbell. For weightlifting it is important that the disk shaped weights are securely held onto the bar. Indeed, considerable damage and/or personal injury could occur if a weight disk slides off of or otherwise detaches from the bar when the barbell is in use.
The weight disks can be prevented from sliding off the bar by a clamp structure which is placed on the bar between the outermost weight disk and the end of the bar. Such a clamp structure must adequately secure to the bar to be effective. In addition, a clamp structure should be easy to install and remove since the clamp may be removed frequently so that the weight configuration can be changed. This can occur because an exercise program requires different weights, or more than one person is using the barbell and each requires different weights.